Blinking Light program for PDP-11

From: Gooijen H <GOOI_at_oce.nl>
Date: Fri Dec 3 01:47:02 2004

The drawback of using the RESET instruction 000005 is noticed
when you have RX01 or RX02 drives connected to your system.
The INIT signal on the UNIBUS, asserted by the execution of
the RESET instruction causes all peripherals attached to reset.
For an RL01/RL02 drive you can probably see a lamp flash on the
front of those drives, but the RX floppy drives "clunk" with
their heads on INIT.
>From experience, running this little blinkenlight program on
an 11/35 is not fun for long, unless you are deaf because the
sound of engaging/disengaging the RX heads is *not* fun.
Sorry that you had to wait a little longer until Guy sent you
that program. I have it too, but could not find it ....

- Henk, PA8PDP.


> -----Original Message-----
> From: cctalk-bounces_at_classiccmp.org
> [mailto:cctalk-bounces_at_classiccmp.org]On Behalf Of Ashley Carder
> Sent: donderdag 2 december 2004 19:33
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: Blinking Light program for PDP-11
>
>
> >Tom Uban wrote:
> >
> > Ashley,
> > Did you get a response on your question? One point
> > to keep in mind is that the various processor types
> > behave slightly differently. The typical method used
> > to do the "Cylon" lamp effect was to use the console
> > switch/display register (777570). A pseudo code program
> > would be something like this (translation left as an
> > exercise for you:-):
> >
> > Write '1' to console display register.
> > Lamp Loop:
> > Load spin count into register 2.
> > Spin Loop:
> > Decrement register 2.
> > Branch if non-zero to Spin Loop.
> >
> > Rotate the console display register value left.
> > Branch to Lamp Loop.
> >
> > This code will continually rotate one lamp from right to
> > left across the display. A more complex version would switch
> > directions when the lamp hits either end.
> >
> > Now for the problem. Only some processors (45, 70, perhaps
> > others, but I don't think the 35 or 40) support display of
> > the console switch/display register.
> >
> > There may be some other more generic method that works on
> > all processors, but I'm not sure what it might be...
>
>
> Hi Tom,
>
> I got a little "single rotating bit" program, coutesy of Guy
> Sotomayor,
> who's been a *BIG* help to me. I used this little program to do some
> basic testing on my PDP-11/40. It continually rotates one
> lamp across
> the display. This program was loaded as follows:
>
> Load address 001000
> Deposit 005000
> Deposit 005200
> Deposit 006100
> Deposit 000005
> Deposit 000775
> Load address 001000 and press Start.
> You should see a bit rotate around on the data LEDs.
>
> If anyone has any more interesting programs that can be toggled in
> for "blinking light" effects, I'd be interested in trying them out.
>
> After toggling in a couple of these types of things with the front
> panel last night, I decided to move on to bigger things. I hooked up
> an RL02 and was able to successfully boot RT11 v5.3, XXDP 2.5,
> and my Wofford Witch RSTS/E v7 system.
>
> Life is good!!!
>
> Ashley
>
>
Received on Fri Dec 03 2004 - 01:47:02 GMT